This invention relates generally to toy vehicles of the type used on a track surface having electrical conductors embedded in the surface thereof, and more particularly to toy vehicles and track which permit reliable operation, with good performance on vertical surfaces. The game of driving and racing small electrified toy vehicles on tracks comprising one or more closed continuous loops has become increasingly popular in recent years. Electric motors mounted in the vehicles are energized through conductors or rails imbedded in the surface of the track, and the vehicles may be remotely controlled. Racing of cars on parallel tracks with various cross-overs, bypasses, obstacles, leaps, and the like is very popular. The cars look like racers and stock cars in miniature and generally there is an effort in design of such toys to achieve simulated realism, for example, illuminated head lamps, motor noise simulators, an ability to steer the vehicles and to operate either in the forward or reverse direction. All this is accomplished with control provided by the operator from a remote location.
However, in order to provide a commercially successful product, excitement as well as realism, for the user and spectator is desirable. High rates of acceleration and high speed are factors adding excitement to the game. However, high accelerations are achieved with vehicles of low mass, but low mass may result in wheel slippage under conditions of rapid starting. High velocities when achieved, frequently result in the vehicle leaving the track on entering curves which are a necessary part of a closed loop track circuit. In earlier models of toy vehicles of the prior art, additional weight was used to keep the vehicles on the track at high velocities, especially on curves. Thus, a conflict existed between low weight-high acceleration performance and requirements for successful high speed operation of the vehicles.
This problem has been overcome in the art by providing magnetic attraction between the vehicle and the track such that magnetic force is combined with the weight of the vehicle in providing a strong holding force between the vehicle and track at high speeds, even around curved segments. Acceleration was also improved as wheel traction was enhanced by the magnetic attraction and vehicle weight could be reduced without slip of the wheels at start-up and without the vehicle leaving the track on turns at high speed.
U.S. Pat. No. 4,031,661, issued June 28, 1977, discloses a refined construction of a vehicle having driving and accelerating properties which are enhanced by magnetic attraction to the power rails embedded in the track. Flux collectors on the side of the motor magnets concentrate the flux and direct the flux for cooperation with the rails. This construction improves the track hugging capabilities of the car while not requiring the relatively greater weight of additional magnets. Thus, performance is benefitted during start-up and at high speeds, especially on curved surfaces.
It would be desirable to enhance the play value of road racing sets by providing vertically extending track sections as well as track sections extending horizontally, upside down or along vertical surfaces. However, conventional toy racing sets do not provide for this. However, such a feature should not interfere with normal track operations.
What is needed is a toy vehicle and track having vertical portions which provides excellent performance on the vertical surfaces without relative loss of performance on the horizontal track surfaces.